Railway sewing machine in combination with a pin-type work holder



Jan. 26, 1965 R. BRIGGS 3,

RAILWAY SEWING MAGHINE IN COMBINATION WITH A PIN-TYPE WORK HOLDER Filed Dec. 28, 1962 4 Sheets-Sheet 2 Jan. 26, 1965 R. BRIGGS 3,167,041

RAILWAY SEWING MAGHINE IN COMBINATION WITH A PIN-TYPE WORK HOLDER Filed Dec. 28, 1962 4 Sheets-Sheet 3 Jan. 26, 1965 R BRIGGS 3,167,041

RAILWAY SEWING MAGHINE IN COMBINATION WITH A PIN-TYPE WORK HOLDER Filed Dec. 28, 1962 4 Sheets-Sheet 4 United States Patent Ofilice 3,167,041 RAILWAY SEWING MACHINE IN (IGMBINATIUN WITH A PIN-TYRE WQRK HGLDER Richard Briggs, Reading, Mass, assignor to Birch Brothers, Ind, Somerville, Mass, a corporation of Massachusetts Filed Dec. 28, 1962, Ser. No. 248,135 4 Claims. (Cl. 112-2 This invention relates to a method and machine for textile stitching and, more particularly, to an improved railway sewing machine of the class commonly utilized for supporting fabric ends of two separate lengths of cloth in a raised position on a railway and sewing the fabric ends together in abutting relationship by means of a traveling stitching head which moves along the railway. In sewing fabric ends as carried out with conventional railway sewing machines, it is customary for the operator to secure the fabric ends in the machine on spaced apart holding pins. The machine is then started and allowed to travel along the railway to apply a series of substantially uniformly spaced stitches. When the stitching operation is completed the operator is required to disengage the sewed fabric portions from the machine and to manually return the stitching head to its starting position.

These steps are time consuming and require operator time which could be advantageously utilized by an operator in preparing additional cloth or fabric ends which are waiting to be sewed. It is, therefore, a chief object of the invention to improve railway stitching machines of the general type indicated and to provide means for automatically carrying out steps which have heretofore been manually performed by the operator as noted above.

Specifically, it is an object of the invention to increase the efficiency of the sewing machine and to effect desirable reduction in operator time and labor required for such sewing operation.

A further object of the invention is to provide in a railway sewing machine of the class described, means for mechanically disengaging and releasing sewed fabric ends immediately after a sewing step is completed.

Still another object is to provide a means for automatically returning the stitching head to a starting position as soon as the sewed fabric ends have become disengaged and allowed to fall away from the machine.

It is still another object of the invention to devise a method of controlling the stitching operation in such a way as to vary the number of stitches applied in the fabric during movement of the stitching head whereby a selectively reinforced stitching effect may be realized at the opposite edge portions of .two abutting fabric ends or at other desired points.

These and other objects and novel features will be more fully understood and appreciated from the following description of a preferred embodiment of the invention selected for purposes of illustration and shown in the accompanying drawings, in which:

FIGURE 1 is a plan view of the improved railway sewing machine of the invention;

FIGURE 2 is a side elevational view of the machine;

FIGURE 3 is a cross section taken on the line 3-3 of FIGURE 1;

FIGURE 4 is a detail perspective view of fabric ends sewed together in accordance with the invention;

FIGURE 5 is a detail cross sectional view taken on the line 5-5.of FIGURE 2;

FIGURE 6 is another detail perspective view of a modified method of sewing fabric ends in accordance with the invention;

FIGURE 7 is a diagrammatic view illustrating electrical support and control means for operating the machine; and

1161M! Patented Jan. 26, 1965 FIGURE 8 is a detail cross sectional view of clutch mechanism for selectively driving the parts noted.

The principal parts of my sewing apparatus include a railway bed, a stitching head and supporting carriage for moving the stitching head along the railway bed, and a power driving mechanism which drives the stitching head and which can also be operated to move the carriage in two directions and at either one of two different speeds.

Referring in detail to the structure shown in the drawings, numeral 2 denotes a stand on which is supported, in a raised position, an elongated railway bed 4. The railway bed is formed at its upper side with a fabric retaining surface 5. Mounted in the railway bed 4 is a horizontally traveling carriage generally denoted by the arrow C. The carriage includes a base member 7 at the underside of which are secured wheel hangers 9 for receiving therein wheels 11 which are arranged to lie in rolling contact with the bottom of the railway bed 4 as is more clearly shown in FIGURES 2 and 3.

Mounted along an inner side of the railway bed 4 is a pin retracting bar 3 which is secured at one end to a spring member 3a. This spring is anchored to a holding rod 3b extending through the railway bed as suggested at the left hand side of FIGURES 1 and 2. At its opposite end the pin retracting bar 3 is attached to a solenoid device 3c secured in the railway bed as indicated at the right hand side of FIGURES l and 2.

Connected to the underside of the pin retracitng bar 3, in notches 3g formed therein, are pin levers as 3d which are pivoted at 32 in the railway bed. The pin levers 3d are of hell crank type and support at upper extremities thereof holding pins as 3 more clearly shownin FIG- URE 2. When the solenoid 3c is energized the retracting bar is moved ahead against the resistance of spring 3a and the levers 3d are pivoted by the retracting bar 3 so that the pins 3 swing downwardly to points below the surface 5 of the railway bed.

It ispointed out that at least two spaced apart pin levers will be employed to hold two fabricle'ngths at their opposite edges and a larger number of pins may be used if desired. Likewise, the spacing of the pin levers and pins may be varied to accommodate different widths of fabrics which are to be sewed.

At the left hand side of the traveling carriage C, as viewed in FIGURES 1 and 2, is located the power driving mechanism comprising an electric motor 6 and a gear reducer R. This drive mechanism furnishes power for driving the traveling carriage along the railway bed 4 when desired and also for operating the stitching head 8 received on the forward end of the carriage as noted in FIGURE 2.

In accordance with the invention, the drive shaft 6a, of motor, 6, is provided with two pulleys and 2 V-belts, B1 and B2 of ditferent ratios. The belts B1 and B2 run over respective idling sheaves K1 and K2 on a gear reducer input shaft G of the gear reducer R as is most clearly shown in FIGURE 3.

Idler pulley K1 is the higher speed pulley and is fixed to a sprocket gear 20 on the input shaft G. Sprocket gear 20 is in turn attached to a clutch plate of an electrically operated clutch mechanism D2.

The clutch mechanism D2 and a portion of the reducer and input shaft are more clearly shown in FIGURE 8. As noted therein the clutch mechanism is made up of a field component F1 keyed to shaft G, and an armature component H1 which is free to turn on the shaft and which is fastened .to sprocket gear 20 and idler pulley Kl.

This entire assembly of pulley, sprocket and clutch plate is normally freei to runon the gear reducer input shaft G until such time as the clutch is energized. The

3 sprocket gear 20 has engaged therearound a sprocket chain 18 which drives the stitching head 8 through a second sprocket gear 16 mounted about a single direction clutch 19 on a stitching head shaft 21 (FIGURE 1).

Idler pulley K2 is the lower speed pulley and, as shown in FIGURE 8, is fixed to a clutch plate H2 of a second electrically operated clutch mechanism D1. Clutch plate H2 is free on shaft G and is adapted to engage with an armature part F2 fixed on shaft G.

As shown in FIGURE 7, the clutch mechanisms D1 and D2 are connected to a source of power in such a way that they are controlled by a two-position toggle switch S1 located at the upper side of a control box 23 as indicated in FIGURE 2.

As will be observed from an inspection of the wiring arrangement of FIGURE 7, both clutches D1 and D2 cannot be engaged or disengaged at the same time since the switch S1 has no neutral position and either one or the other of the clutches is therefore engaged at all times when power is on. Thus it will be apparent that when the motor 6 is running, both the V-belts turn and one or the other will drive the gear reducer input shaft G through the particular clutch mechanism which is energized.

The gear reducer R is further provided with an output shaft 25 extending through a lower side thereof and this shaft rotates a gear 26 fixed at the lower end of the shaft as illustrated in FIGURE 3. Gear 26 is arranged to mesh with an elongated rack element 28 mounted on a channel frame 30 in the railway bed as further noted in FIGURE 3.

Supported in rolling contact with a rear surface of the rack mechanism is a guide roller 32 which is supported on a spindle 34 extending downwardly from the underside of the carriage base 7. By means of this arrangement it will be seen that the rack 28 and gear 26 may be firmly held against one another at all points during travel of the carriage along the railway bed.

It is pointed out that the speed of travel of the carriage will depend on which one of the pulleys is in driving engagement with the input shaft through its respective clutch mechanism. However, the stitching head 8 is driven at one constant speed during movement of the carriage in a forward direction and operation of the stitching head stops during rearward movement of the carriage. When the stitching head 8 reaches a point where the fabric ends have been completely sewed together, forward travel of the carriage C is interrupted. In accordance with the invention arresting the carriage is accomplished by a limit switch L1 having a pivoted arm L2 which normally engages along an inner vertical surface of the railway bed as shown in FIGURES l and 3. At the forwardmost point in its travel the arm L2 engages over an angled projection P1 which causes the arm to pivot. Movement of arm L2 opens the operating circuit for the motor 6 and at the same time causes the solenoid 30 to become energized so that the holding pins are retracted.

At this point I further provide for a dwell period during which the motor is maintained in an inoperative state. The dwell period may be of relatively short duration as, for example, 3 to seconds and its purpose is to provide an interval during which the sewed fabric ends, having been released for retraction by the holding pins, may fall away from the surface 5 of the railway bed. Thus the need for manual disengagement of sewed fabric ends from the holding pins is eliminated with a saving of the operators time.

Thereafter, the motor is automatically reversed and the carriage is driven in a rearward direction until a second limit switch L3, having an arm L4, moves against projection L5 which stops the motor and locates the carriage in its original starting position. This eliminates any manual return of the carriage by the operator so that he is free to start another stitching operation.

The operations described are controlled by a series of 4 relays which are actuated by the limit switches L1 and L3 and also by 3 contact push buttons. The push buttons are shown in FIGURE 2 and include a forward push button PBl, a reverse push button PB2 and a stop push button PBS. The relays are shown in FIGURE 7 and include a motor starting power relay R3, a reverse relay R4 and a time delay relay R5. Power from the main source of supply runs to a rectifier R6 which is in turn connected to the clutches D1 and D2 and switch S1 so that one or the other of the clutch mechanisms may be energized by operating the toggle switch S1 as desired.

In operation with power on, the operator places two fabric ends of fabric lengths W1 and W2 (FIGURE 3) in an engaged position with respect to the holding pins 3] on the railway surface 5. The toggle switch S1 is placed in a position to provide a desired travel speed for the carriage C and the forward push button PB1 is actuated.

The carriage with the stitching head moves along the railway bed and the stitching head applies stitches Z1 to secure the two fabric ends together as shown in FIGURE 4. When the limit switch arm L2 is pivoted by the projection P1 the carriage comes to rest, the stitching head is stopped, and the motor 6 becomes inoperative.

These steps are accomplished by the limit switch L1 breaking the circuit to the power relay R3 and at the same time the limit switch L1 energizes a circuit through the solenoid 30 as shown in FIGURE 7 which acts on the pin levers 3e through the retracting rod 3 and the holding pins are pivoted downwardly away from the fabric. The sewed portions are then free to fall away from the railway bed wthout further handling by the Operator.

In order to insure that this disengagement of the fabric may have sufiicient opportunity to occur without interference with the stiching mechanism, a short dwell period is provided by means of the time delay relay R5 which holds all of the apparatus in an inoperative state.

At the end of the dwell period a reverse movement of the motor is initiated by means of the reverse relay R4 and the carriage is driven back towards its starting position. During this latter movement of the carriage the stitching head is at rest since it is only operated through the single direction clutch 19 earlier described. During the period that the carriage starts to return to its starting position, the solenoid 3c continues to hold the pins down in their fully retracted position until the limit switch L1 is completely disengaged from the projection P1. Thereafter, the limit switch L3 engages the projection L5 which positions the carriage in its original starting position.

The stop push button PB3 and the reverse push button PB2 are provided for emergency use to either stop or reverse the carriage travel should it become desirable or necessary at any time during the sewing operation and before the pre-set travel has been completed.

This operation provides a conventional sewed seam having stitches of some desired spacing applied uniformly along the fabric ends. However, as previously noted, the machine may be operated so as to provide for changing the stitch lengths to impart desirable reinforcing at se lected points along the fabric ends as illustrated by the stitches Z2 in FIGURE 6. For example, in a typical operation, stitch lengths may be referred to as the number of stitches per linear inch of seam and as illustrative thereof seven stitches per inch may be employed. However, in accordance with the invention by the two-speed mechanism described, the speed of the carriage may be controlled to provide for a larger number of stitches as fourteen stitches per inch. This is accomplished through moving the toggle switch S1 from one position to the other as earlier suggested.

It is pointed out that the stitches may be desirably increased in number per unit length of seam at the two opposite edges of the fabric lengths so as to provide a reinforced section at each end of the seam as comprised by stitches Z2 and intermedaite stitches Z3 as illustrated in FIGURE 6. Similarly, reinforcing may be carried out at other desired points along the seam.

Important advantages are realized by the disclosed invention, both in the sewing steps and the work done in the fabric. Thus manual disengagement of the sewed fabric is no longer necessary and this frees the operator for other work. Moreover, the conventional practice of manually returning the carriage to a starting position is no longer necessary as retraction of the carriage occurs automatically. A desirable control of the placing and occurrence of stitches is made possible and a saving of both time and thread is realized in comparison with a continuous fine stitch. There is, furthermore, a more desirable seam than one with a continuous coarse stitch in that the stitches of the seam where it is most likely to pull out a reinforcing of fine stitching may be introduced.

The method and apparatus of the invention has been described with reference to one preferred embodiment. However, it may be desired to practice the invention in other forms. For example, I may desire to obtain a variation in stitching and reinforcing for other purposes by controlling the speed of the stitching head utilizing conventional controls which are supplied with stitching machines of the class indicated and maintaining the return travel of the carriage constant. I may also desire to modify the electrical control and the holding pin mechanism in various ways and other changes and modifications may be resorted to within the scope of the appended claims.

I claim:

1. in the railway sewing machine of the class having a stand and a railway bed mounted thereon, the combination of retractable holding pins projecting upwardly from an upper surface of the railway bed to receive and hold fabric ends to be sewn, a traveling carriage movable along the railway bed, a power driven stitching head supported on the traveling carriage and constructed and arranged to apply stitches to said fabric ends received on the said holding pins, means for controlling the placement of stitches applied by the stitching head during movement of the traveling carriage along the railway bed and means responsive to the travelling carriage for moving the holding pins downwardly out of contact with the cloth at one point in the movement of the carriage.

2. In a railway sewing machine of the class having a stand and a railway bed mounted thereon, adjustable pinholding mechanism for securing abutting edges of fabric ends on the railway bed and a power driven stitching head constructed and arranged to travel along the railway and apply stitches to the fabric ends, said pin-holding mechanism including a pin retracting bar having pins received therein and solenoid means responsive to travel of the stitching head for moving the pin-holding bar and pins and disengaging the pins from the fabric ends at the termination of a predetermined stitching period.

3. In a railway sewing machine of the class having a stand and a railway bed mounted thereon, the combination of pin holding elements for securing fabric ends on the railway bed, retractor bar means for mechanically retracting the holding pin elements, a reversible traveling carriage mounted for movement along the railway bed, a stitching head on the carriage, power driving means for operating said traveling carriage, said power driving means including a single direction clutch mechanism for actuating said stitching head during movement of the carriage in one direction, electromechanical means for controlling the movement of the carriage and operation of the stitching head, said electromechanical means including a solenoid device for actuating said retractor bar means when the carriage has completed its forward travel.

4. A structure according to claim 3 in which the electromechanical means includes (a) a limit switch attached to the carriage and adapted to be actuated during forward travel of the carriage,

(b) a power relay for controlling the power driving means and responsive to the said limit switch,

(c) a time delay relay for holding the power driving means in an inoperative state for the short interval when the power relay has been operated by the limit switch, and

(d) a reversing relay which reverses the power driving means to return the carriage to a starting position after a short interval determined by the said time delay relay.

References Cited by the Examiner UNITED STATES PATENTS 1,949,262 2/34 Stromelly 26953 2,243,668 5/41 Cash 269-53 2,425,312 8/47 Gower 318-285 2,634,390 4/53 Kennedy et al. 318-285 2,724,352 11/55 Gentry et al 1122 3,006,209 10/61 Stromberg 1122 3,009,428 11/61 Coolidge 112-2 3,073,267 1/63 Reeber et al 112-2 3,082,719 3/63 Zeitlin 1122 JORDAN FRANKLIN, Primary Examiner. 

1. IN THE RAILWAY SEWING MACHINE OF THE CLASS HAVING A STAND AND A RAILWAY BED MOUNTED THEREON, THE COMBINATION OF A RETRECTABLE HOLDING PINS PROJECTING UPWARDLY FROM AN UPPER SURFACE OF THE RAILWAY BED TO RECEIVE AND HOLD FABRIC ENDS TO BE SEWN, A TRAVELING CARRIAGE MOVABLE ALONG THE RAILWAY BED, A POWER DRIVEN STITCHING HEAD SUPPORTED ON THE TRAVELING CARRIAGE AND CONSTRUCTED AND ARRANGED TO APPLY STITCHES TO SAID FABRIC ENDS RECEIVED ON THE SAID HOLDING PINS, MEANS FOR CONTROLLING THE PLACEMENT OF STITCHES APPLIED BY THE STITCHING HEAD DURING MOVEMENT OF THE TRAVELING CARRIAGE ALONG THE RAILWAY BED AND MEANS RESPONSIVE TO THE TRAVELLING CARRIAGE FOR MOVING THE HOLDING PINS DOWNWARDLY OUT OF CONTACT WITH THE CLOTH AT ONE POINT IN THE MOVEMENT OF THE CARRIAGE. 